Steam pumping-engine



I ZSheets-Sheet 1. E. COPE 8: J. R. MAXWELL.

Steam Pumping-Engine.

Patented April 27, 1880.

6 8 L IN VENTORS H Arm/WE? Z-Sheets-Sheet 2. E. COPE & JLR. MAXWELL.

Steam Pumping-Engine v) Patented April 27,1880.

-I J N RN a w F fi-I W PJ Q INVENTOR WITNESSES ATTORNEY N. PETERS. PNQTO UYBOGRAPH UNITED STATES PAT NT Gr ntee.

EZRA COPE, OF HAMILTON, AND JAMES R. MAXIVELL, OF CINCINNATI, OHIO.

STEAM PUMPING-ENGINE.

SPECIFICATION forming part of Letters Patent No. 226,837, dated April 27, 1880.

Application filed Febrpaz j, 13, LQEL. ri A l 7 To all whom it may concerzr:

Be it known that-we, EZRA Corn, of Hamilton, Butler county, Ohio, and drums It. MAX- WELL, of lincinnati, Hamilton county, Ohio, have invented certain new and useful Improvements in Steam Pumping-Engines, of

, which the following is specification.

Our invention relates to compound engines used for pumping purposes. Such engines, as generally constructed, involve a ratio of expansion fixed by the proportion of the cylinders to each other.

Assuming the prime cylinder to receive steam during its full stroke, it has followed that the ratio of expansion depended entirely upon. the proportion which the practical volume of the prime cylinder bore to the practical volume of the second cylinder. These volumes being fixed,a change in the ratio of expansion could not be efiected. A change in quantity of work performed was to be effected by a change in thepressure of steam admitted to the prime cylinder, and as the proportions of the cylinders had been adapted to a certain steam-pressure, it followed that a change in the prime pressure involved some disproportion between the second cylinders power and its load. To secure the essential uniformity of motion this disproportion required a remedy, and this remedy has generally consisted of judicious throttling between the cylinders, and in some cases of an increasing of the resistance by reducing the value of the vacuum or otherwise.

In water-Works machinery it is especially desirable that provision should be made against accident, and also that a reserve power should be at hand for extra duty.

In compound engines heretofore constructed it has been the practice, in case the enginevalves were of the steam -moved variety, to part with the steam exhausted from the auxiliary cylinders without exacting further duty from it.

The objects of our invention are to provide a compound pumping engine in which the proportion between the practical volume of the prime cylinder and the practical volume of the final cylinder is self-adapting to the requirements to provide a compound pumping-engine which, if desired, may be operated as one or two simple engines at prime pressure; and to provide a pumping-engine in which" any steam which may be exhausted from auxiliary cylinders is caused to perform further useful work.

In the accompanying drawings, Figure l is a plan of our improved pumpingengine, and Fig. 2 a diagram exhibiting the relation of parts.

In Fig. l, A is the primal cylinder.- It receives its steam from the boiler through pipe Y. The valve-gear may be of anysuitable character. The piston of the primal cylinder operates a pump, D, delivering into the main L.

The device, as thus far describe-d, constitutes a steam pumping-engine capable of motion upon being supplied with steam.

The steam-cylinder A and the pump D are to be so proportioned to each other that the device will do its proper duty.

The primal cylinder A exhausts its steam into the receiver H.

P is the second cylinder. It has independent valve-gear of any suitable character. It operates a pump, V, delivering into the common main L. This cylinder receives its steam from the receiver H, and exhausts it at VVinto the atmosphere or condenser.

The secondary cylinder P and pump V are to be so proportioned to each other that the pump-plunger will accomplish its work when the secondary piston is acted upon by the steam from the receiver, H.

It will, of course, be understood that the usual back-pressure becomes an element in the calculation of the power of the primal cylinder. This usual back-pressure is that due to the fact that the primal cylinder exhausts its steam against this resistance of the secondary piston, instead of into the atmosphere or condenser. By usual back is meant the back-pressure usual to compound engines.

Assume that the power of each of these in- 9 5 dependent engines is the same, and that the resistance of each pump is the same, then will each do the same amount of work and accomplish an equal number of strokes. The expansion of the steam used may be measured di- 10o rectly by the proportion of the cylinders, with their clearances, of course. Assume now that some of the conditions become changed, that the steam- 'n'essure becomes augmented, or that the resistance decreases, then will the velocity of both engines increase, but not in the same degree in each. Those familiar with the action of compound engines will readily understand that if the power of the two engines were equal at a certain primal pressure, the power of the two will not be equal at a higher pressure. The equalization of the powers had reference to a definite primal pressure. The power of the primal engine being enhanced by an' increase of the primal pressure, "the sweet ess secondary cylinder becomes enhanced in a higher degree on account of its larger area. The power of the secondary engine being now greater than that of the primal engine, the former will, of course, make the greater number of strokes and perform the greater part of the work. The velocity of the two pistons not being the same, it follows that the ratio of expansion can no longer be measured by the proportion of the pistons. The practical volume of each cylinder, the relative velocity of each piston entering into consideration, now becomes the measure of the expansion. In the case assumed the expansion has increased, and it will be seen that the expansion-grade will alter itself to suit capacity for action.

The primal engine being by any means held to a uniform speed, the secondary engine will regulate its own velocity by the available energy left in the steam it receives from the primal engine.

If there is sufficient energy in the supply to causea movement, the secondary engine makes that movement. If the energy is too low, the secondary piston will reduce its velocity, and even allow the pressure to accumulate in the receiver. If the energy should be excessive, the secondary engine will accelerate its velocity and work the receiver-pressure down. In fact, the velocity of the secondary piston will always be such as to maintain an exact workingpressure in the receiver, and in practice we find that with a judicious proportioning of the two engines the discrepancy between the velocity of the twopistons will be very trifling, while the latent capacity for any Variation possible is always present. It should also be noticed that if the secondary piston, by reducing its velocity, demands a further accumulation in the receiver, this enhancement of the receiver-pressure will indicate itself as backpressure on the primal piston, which, meeting thus with increased resistance, will decrease its speed, thus tending to equalize the velocity of the two.

Under all conditions it will be seen that the proportion of the practical volumes of the cylinders, and consequently the ratio of expansion, will alter itself to suit the conditions. The plan may be carried still further by adding more cylinders and pumps in an obvious manner.

The diagram, Fig. 2, illustrates the manner of connecting the primal and secondary engines so that they may run compound, as described, or as one or. two simple engines.

First, as a compound engine: Steam from boiler enters primal engine A through pipe Y, thence exhausting through pipe G into receiver, thence through pipe M to secondary cylinder 1?, thence through pipe W to atmosphere, or condenser, or third cylinder. Should the valve-gear be of the steam-moved variety, the steam for their operation is received from the boiler through pipes O and R, and exhausted through pipes F and 0 into the receiver, where it is utilized in further action. Obviously thepipin g used in the transmission of the steam for tl'ieauxiliary or valve cylinders may find a substitute in properly constructed and arranged ports inthe connection between the main cylinders and their respective auxiliary cylinders. 2

Second, as independent high-pressure engines: Valve N is to be closed, valves (41,11, and 0 opened. Steam from boiler enters small engine'A through pipe Y, and is exhausted through pipe Gr (receiver H having no office in the present case) and pipe I to atmosphere, or, if desired, to condenser, which would make a condensing engine of the small engine. Steam from boiler, through pipe d, enters larger engine I, whence it is exhausted through pipe W into atmosphere or condenser, the steam from the auxiliary cylinders exhausting into the atmosphere or condenser through receiver H and pipe I. The pipes I and W may join and have common outlet.

Third, either engine may run while the other is idle, the two valves b and 6 being used in an obvious manner. The arrangement of the gates in the discharge-branches of the two self in connection with the operation of one engine while the other is idle.

By our arrangement it is seen that the requirements of municipal and other water-works are particularly and nicely fulfilled.

The engine may work normally as a compound engine. For heavy duty the large engine may be worked at primal pressure, and either engine may be run while the other is idle or being repaired.

In connection with the arrangement of pipes we desire to call attention to the fact that'the location of the valvee near the boiler, as shown, allows the pipe d to become an element of the receiver-volume when the engines are working compound, and that for its normal functions the valve 0, or another valve, may be located in the pipe d nearer the larger cylindersay at f.

We claim as our invention- 1. In a steam. pumping-engine, the combination, with an independently-acting primary engine operating a pump delivering into a main, and a receiver into which the primary engine exhausts its steam, of an independently-acting secondary engine operating a pump pumps, it is thought, will properly suggest it- IIO delivering into a main common with that of the pump operated by the primary engine, the secondary engine being so arranged as to receive its steam from said receiver, all constructed and arranged for operation substantially as set forth.

2. In a steam pumping-engine, the combination, with an independently-acting primary engine, a receiver, and an independently-acting secondary engine, of a conducting-pipe and valve between the primal source of steam-sup ply and the secondary engine, a conductingpipe and valve between the receiver and secondary engine, and an exhaust-conductor and valve between the primal engine and the atmosphere or condenser, whereby either or both of the engines may be run independently by steam from the primal source of supply, all constructed and arranged for operation substantially as set forth.

3. In a steam pumping-engine, the combination, with a primary engine, a receiver, a secondary engine, and a conductor between the primal source of supply and the secondary engine, of a valve in the said conductor, located near the source of supply, whereby said conductor is caused to increase the practical volume of the intermediate receiver, all constructed and arranged for operation substantially as set forth.

4. In a steam pumpingengine, the combination, with an intermediate receiver and a primary and a secondary engine, either or both of which engines have steam-moved valves, of a conductor or conductors between the auxiliary cylinder or auxiliary cylinders of said engines and said receiver, whereby the steam which has been used to move said valve or valves is caused to operate further in the secondary engine, all constructed and arranged for operation substantially as set forth.

EZRA COPE. JAMES R. MAXWELL.

Witnesses:

ISRAEL WILLIAMS, JAMES B. SMITH. 

